Exam info

Most important is:

Binary number system (and conversion)

What CPU is and how it works

Basic computer components

Lecture notes

Transistors → Can amplify or switch eletronic signals and eletrical power. Made from semiconductors. They can control flow of electricity by applying a small input signal
- Collector → collects the current
- Base → receives the input signal which turns on/off the switch
- Emitter → where the current is released if the base receives an input
Current → flow of eletric charge through a current, measured in Ampere. In CS we consider the states when the current flows (1) or when it doesn’t (0)
Circuit → Multiple transistors mixed together
Gate → combined circuits/transistors
- AND ( $.$ ) Gate → Both input need to be true
- OR Gate ( $+$ ) → Either input must be true
- XOR Gate ( $\oplus$ )→ Accepts only one true input → $A . B^{'} + A^{'} . B$
- NOT ( $‘$ ) → inverts the input

Abstraction of basic circuits → Somewhat smarter than normal circuits ALU does not have excess memory → it cannot store the processed information

Exam info

Most complicated in the exam will be basic combinational circuits such as XOR (slide 19)

Arithmetic logic unit
Random Access Memory → stores data and instructions that the CPU accesses during execution. Volatile memory.
Registers → Temporary memory that CPU’s have direct access to
Control unit → Receives instruction from memory and controls flow of data within the CPU. Interprets the Opcode to determine the operation to be performed by ALU or memory

Instructions set and machine code

==Instruction set== → Collections of instructions that the CPU can execute. Operations that you can perform on the computer. They are identified by a certain Opcode.
- RISC → Reduced Instructions Set → mostly in phones, low computational power
- CISC → Complex Instructions Set

Moore’s Law

The number of transistors in a dense integrated circuit doubles about every two years.